The Maxxis tires on my last fiver lasted just over 3 yrs. In temps over 100 F, one tire lost pressure. Fortunately with a TPMS and just coming into a town, I was able to stop before it lost all air pressure. The tire looked so good I took it to a tire shop thinking it could be repaired. Instead it had multiple leaks right at the transition from tread to sidewall. Next day I had to tow the fiver 40 miles to the nearest Discount Tire and while the remaining tires didn't loose air pressure, they ballooned so bad they were rubbing against the fender skirt and underside of the floor at even the slightest bump. So all four tires were on the verge of throwing the tread. These were 15" Maxxis LR E tires and just 39 months old per date code.
I have 16" wheels on my present rig and run LTs that are currently 53 months old.